This classroom experiment promotes discussion of the social origins and characteristics of money. Students take the roles of traders who face a double coincidence of wants problem. As they recognize the benefits of overcoming trading frictions, students spontaneously begin using a consumption good as a medium of exchange. The setting comes from Duffy and Och's (1999) experimental version of the Kiyotaki-Wright (1989) search model of money. In the Kiyotaki-Wright (KW) environment, agents specialize in production, but consume a good other than their own product. Specialization combined with decentralized trading introduces the double coincidence of wants problem. In fact, no one could trade if each person held out for his consumption good. For trade to occur, at least some people must be willing to accept a good which they do not intend to consume, but which they hope to trade later for their consumption good. In other words, some people must be willing to accept a medium of exchange. When there exists an item generally accepted as a medium of exchange, then that item is money. Thus the KW setting captures money in its essential role as a medium of exchange. Here, using a medium of exchange reduces the cost of searching for a trading partner who has what you want and wants what you have.